Elapsed time indicating mechanism



April 1969 M. H. WOLFGANG 3,440,369

ELAPSED TIME INDICATING MECHANISM Filed Nov. 14. 1966 FIG. 1

' 9 INVENTOR MORTON WOLFGANG ATTORNEY United States Patent US. Cl. 20038 9 Claims This invention relates to a timer capable of giving an electrical indication at the end of an elapsed time and incorporating an indicating mechanism to show the passage of time during the period of operation.

In the growing field of coin-operated devices there is an increasing awareness that one who uses such devices may wish to know reasonably accurately the amount of time that has passed since the use began and, more particularly, the amount of time still remaining before the end of the period for which he has paid. This is particularly true in the case of those coin-operated devices that require the user to carry out certain tasks himself during the time paid for. If, for example, the device is a coin-operated car wash mechanism capable of dispensing either clear water or water containing a detergent, and the user has paid for a total of five minutes, it is important to know how much of that time has elapsed at any given moment so that he can govern his actions and not have the time run out while the car is covered with suds or with only a portion of some panels completely washed. While the user can refer to a standard clock or watch and make mental calculations necessary to determine the amount of time elapsed, it is not convenient to rely on this type of timing because too often a user will forget to note the starting time and, therefore, will be unable to predict the end of the period of usage. It would also be possible to provide a clock similar to a stop watch that could be set into the operation at the beginning of the timed interval and would indicate the passage of time within that interval, but such clocks are relatively expensive, may be stolen, and are not absolutely tied to the operation of the timer itself so as to preclude any possibility that there might be a discrepancy between the time indicated on the clock and the interval measured by the timer.

It is one of the objects of the present invention to provide an improved timer particularly for use in coin-operated apparatus and incorporating a time indicating mechanism that will invariably indicate the exact amount of time remaining in the interval of use.

It is a further object to provide a combined timer and indicator capable of being set easily for different periods and intervals of time per coin.

Further objects will become apparent-to those skilled in the art in the following specification and claims together with the drawings.

FIG. 1 is a front elevational view of the timing apparatus of the present invention including a fragment of the indicating portion;

FIG. 2 shows a top view of the apparatus of FIG. 1; and

FIG. 3 is an exploded perspective view of the ratchet wheel and cam of FIGS. 1 and 2.

The timing and indicating apparatus of the present invention is based upon the well-known concept of driving a shaft at a fixed speed to change the position of a cam at a rate which is a linear function of time. The apparatus also includes means to preposition the cam, for example by means of a solenoid which moves the cam a certain distance each time the solenoid is actuated. The solenoid in turn may be under the control of a coin acceptance mechanism so that the prepositioning of the cam is determined by the insertion of a coin, although in certain modified embodiments the mechanism may be set for 3,440,369 Patented Apr. 22, 1969 operation by more than one coin. The cam is driven by an escapement mechanism comprising a ratchet wheel, a driving spring to rotate the wheel in one direction, a pawl to control the rotation of the wheel in that direction in incremental steps, and a sequencing wheel connected to a constant speed motor to be driven thereby and having an actuating member that engages the pawl to withdraw it far enough to permit the ratchet wheel to move forward. In certain embodiments the sequencing wheel can have more than one actuating member, and it maybe two-sided with a certain number of actuating members on one side and a different number on the other side so that the same wheel can be used to provide different timed intervals merely by turning the wheel over, since the duration of each interval is determined by how frequently the sequencing wheel strikes the pawl to permit the ratchet.

wheel and thus the cam to move forward an incremental amount.

Connected to the shaft of the motor that drives the sequencing wheel is an indicator such as a pointer that cooperates with a dial on the outer face of the structure that houses the timing mechanism. Since the indicator is connected directly to the motor that drives the timing mechanism, any interruption in the operation of the motor will be directly shown by the indicator and as a result it will be impossible for the user of the apparatus to be misled into thinking that he has a longer period of use remaining than is actually the case. Moreover, since the indicating mechanism is part of the timing mechanism and is useless apart therefrom, there will be no likelihood that the indicating mechanism will be stolen.

In the apparatus in FIGS. 1 and 2, a motor 11 mounted on a base 10 drives a shaft 12 on which is mounted a sequencing wheel 13 having, on the surface facing upward in the drawing, one actuating member 14 near the perimeter thereof. Although not shown in FIG. 1, the wheel 13 has eight actuating members evenly spaced near its perimeter on the other side. Moreover, the wheel is preferably made of plastic, and any desired number of actuating members can be easily cut, broken off, or otherwise removed from either side of the wheel to effect different operating speeds of the apparatus. However, for the immediate purpose only one actuating member is required. A stationary shaft 16 supports a ratchet wheel 17 and a cam 18 which are keyed together and held in place by a washer 19. A pawl 21 having four arms 22-25 is mounted on another stationary shaft 27 and held in place by a washer 28. Three of the arms 22-24 have projections 22a-24a, respectively, to engage either the tripping wheel 13 or the ratchet wheel 17. A return spring 29 is connected from the fourth arm 25 to a fixed lug 31 to urge the pawl to rotate counterclockwise as shown in the drawing in FIG. 1.

The ratchet Wheel 17 and the cam 18 are rotated clockwise to their initially set position by impulse forces provided by the armature 32 of a solenoid 33. The solenoid is mounted on a pivotal frame 34, which has a base portion 34a parallel to the base plate 10 and an outwardly extending flange 34b to which the coil 35 of the solenoid is rigidly attached. A spring 36 is stretched between a fixed lug 37 and the flange 34b to pivot the solenoid about a fixed pin 38. A small flap 39 pressed out of the base 10 overlies the outer end of the base member 34 to prevent the latter from being bent away from the base 10 and at the same time the flap engages an edge 340 of the member 34 to limit clockwise rotation of the member in response to the force of the spring 36. The member 34 has another flange 34d against which one end of the armature of the solenoid is pressed by the force of a spring 41. The other end of the armature has a plastic cylinder 42 fitted over it to act as a buffer when the solenoid is energized and the armature is 3 forced against one of the teeth of the ratchet wheel 17.

A switch 43 is rigidly attached to the base 10, or to a bracket thereon, and has an arm 43a that engages the cam 18 to be actuated thereby. The switch controls the apparatus (not shown) the operation of which is to be timed, whether that apparatus be a coin-operated washing device or any other apparatus that must operate or be restrained from operation for a predetermined interval. For this purpose the switch 43 may be either a normallyclosed or normally-open switch as required. In addition, the switch may have a second set of contacts to control the operation of the motor 11, these contacts being so arranged that the motor will be energized as soon as the cam 18 is moved away from its rest position and will continue to be energized until the cam returns to that position.

The operation of the apparatus of FIGS. 1 and 2 be gins with the energization of the coil 35 in response to control by a coin acceptance mechanism (not shown). This energization causes the armature 32 to move forward and to rotate the ratchet wheel 17, together with the attached cam 18, in the clockwise direction a distance equal to the space between successive teeth. As a result, the projection 22a slides over one tooth on the ratchet wheel 17 and is engaged behind it to hold the ratchet wheel and cam in their new position. The motion of the cam causes the arm 43a to be pivoted clockwise as the end of the arm rides along the surface of the cam 18 thereby actuating the switch 43 which energizes the motor 11 and at the same time actuates the apparatus that is being controlled.

When the motor 11 is first energized, the actuating member 14 is immediately behind the projection 23a in the position shown in FIG. 1 and the motor drives the disc or sequencing wheel 13 counterclockwise through a full revolution. As the sequencing wheel 13 nearly completes a revolution, its actuating member 14 engages the opposite side projection 23a and causes the pawl 21 to pivot clockwise to disengage the projection 22a from the tooth of the ratchet wheel 17 thereby permitting the spring 29 to rotate the ratchet wheel counterclockwise. The pivoting motion of the pawl 21 that causes the projection 22a to become disengaged from the ratchet wheel 17 also causes the projection 24a to move into position to stop the motion of the ratchet wheel 17 before it has pivoted through an angle equal to the distance between two adjacent teeth, so that the cam-following end of the arm 43a is still on the high portion of the cam 18 and cannot drop into the notch until the sequencing wheel 13 has rotated far enough to move the actuating member 14 past the projection 23a. Then the pawl 21 is pulled out of the way by the spring 29, allowing the ratchet wheel 17 to move counterclockwise the short distance necessary to cause one of the teeth to engage the projection 22a. This slight forward motion is enough to permit the 'arm 43a to drop into the notch in the cam 18, thus permitting the switch 43 to return to its initial condition whereby both the motor 11 and the apparatus controlled by the timer will be turned off.

The indicator portion of the mechanism includes a dial having numerals 44 and a hand 46. Since the sequencing wheel 13 has only one actuating member 14 on it, it must rotate through a 360 degree angle in completing the foregoing operation. The hand 46 is affixed to the same shaft 12 as the sequencing wheel and thus it too will rotate one full revolution. In doing so it will traverse the dial and point successively to each of the numerals 44 and it will thus give an indication at all times of the amount of time that has elapsed since thebeginning of the timed interval and a correlative indication of the time that remains before the end of the interval.

For some types of operation it may be desired to use a different type of cam in which the arm 43a of the switch is raised for only a small part of the revolution of the cam rather than being raised for a major part of 4 each revolution. FIG. 3 shows the arrangement of the cam which makes both types of operation possible with one structure where it may be seen that the ratchet wheel 17 has a plurality of holes 47 equal in number to the number of teeth and equally spaced around the center. The ratchet wheel 17 also has at least a pair of holes 48 spaced radially inwardly from the holes 47. The exploded view of the ratchet wheel 17 and cam in FIG. 3 shows a pair of posts 49 extending from the inner surface of the cam 18 and in the proper position to engage the holes 48. When the cam 18 and the ratchet wheel 17 are thus assembled, the cam 18 will be in the proper position to engage the end of the arm 43a.

The cam can also be reversed with respect to the ratchet wheel 17, and if that is done, three equally spaced projections 51 will engage three of the outer holes 47. This reversal of the cam places the section 18a of the cam in position to be contacted by the end of the arm 43a. Moreover, since the projections 51 are equally spaced, the cam may be placed in as many angular orientations as there are holes in the set of holes 47. This permits the raised portion 18b of the cam to be oriented anywhere around the circle and, therefore, any number of steps away from a fixed position known as a home position. The location of the home position may be determined by the relation between a projection 52 on the ratchet wheel 17 and a fixed stop 53 that extends upwardly from the base 10 as shown in FIG. 2. This stop and the projection 52 also form convenient means to which the drive spring 54 of the ratchet and cam assembly may be attached to furnish the power to rotate this assembly back to its initial position as the ratchet wheel is released step by step by the pawl 21.

What is claimed is:

1. Elapsed time measuring apparatus comprising: a constant speed motor; a tripping wheel connected to said motor to be driven thereby; a ratchet wheel; a spring urging said ratchet wheel to rotate in one direction; solenoid means to engage said ratchet wheel to rotate the same in steps in the opposite direction; a pawl; a second spring biasing said pawl into contact with said ratchet wheel to prevent rotation thereof in said one direction; means on said pawl engaging said tripping wheel to be actuated thereby to remove said pawl out of engagement with said ratchet wheel to permit said ratchet wheel to turn; a cam connected to said ratchet wheel to rotate therewith; a switch engaging said cam to be actuated thereby when said cam reaches a predetermined position; and an indicator connected to said shaft to indicate the time remaining before the end of the interval being measured.

2. The apparatus of claim 1 in which said pawl comprises, in addition: an arm engaging said ratchet wheel when said means on said pawl is actuated by said tripping wheel whereby said arm prevents said ratchet wheel from moving more than one step at a time.

3. The apparatus of claim 2 in which said arm is resilient to flex under pressure when said tripping wheel engages said pawl and said ratchet wheel is in a position beyond which it will not move.

4. The apparatus of claim 1 in which said ratchet wheel comprises a stop and said apparatus comprises a fixed stop engageable with said stop on said ratchet wheel to form a fixed limit to the rotation of said ratchet wheel.

5. The apparatus of claim 1 in which said solenoid means comprises a coil, an armature longitudinally movable within said coil, a third spring urging said armature away from engagement with said ratchet wheel; means pivotally supporting said solenoid means, and a fourth spring to urge said solenoid means into position in which said armature is aligned with one tooth on said ratchet wheel.

6. Elapsed time measuring apparatus comprising; a constant speed motor; a shaft connected to said motor; a sequencing member connected to said motor to be driven thereby; a detent wheel; first means for setting detent wheel to a first predetermined relative position; second means controlled by said sequencing member for controlling movement of said detent wheel to a second relative position; a switch; third means controlled by said detent wheel to actuate said switch in one sense when said detent wheel is in said first predetermined relative position and to actuate said switch in the opposite sense when said detent wheel reaches said second relative posilion at the end of an interval of time being measured; and an ndicator connected to said shaft to indicate the time remaining before the end of the interval of time being measured.

7. The apparatus of claim 6 in which said detent wheel is a ratchet wheel.

8. The apparatus of claim 7 in which said first means comprises a solenoid having an armature that engages said ratchet wheel to drive said ratchet wheel in one direction, and said second means comprises a pawl enaging said ratchet wheel.

9. The apparatus of claim 6 in which said third means comprises a cam adjusta-bly attached to said detent wheel and having at least two cam surface portions, said switch having an arm engaging said cam surface.

References Cited UNITED STATES PATENTS ROBERT K. SCHAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner.

US. Cl. X.R. 335-68 

6. ELAPSED TIME MEASURING APPARATUS COMPRISING; A CONSTANT SPEED MOTOR; A SHAFT CONNECTED TO SAID MOTOR; A SEQUENCING MEMBER CONNECTED TO SAID MOTOR TO BE DRIVEN THEREBY; A DETENT WHEEL; FIRST MEANS FOR SETTING DETENT WHEEL TO A FIRST PREDETERMINED RELATIVE POSITION; SECOND MEANS CONTROLLED BY SAID SEQUENCING MEMBER FOR CONTROLLING MOVEMENT OF SAID DETENT WHEEL TO A SECOND RELATIVE POSITION; A SWITCH; THIRD MEANS CONTROLLED BY SAID DETENT WHEEL TO ACTUATE SAID SWITCH IN ONE SENSE WHEN SAID DETENT WHEEL IS IN SAID FIRST PREDETERMINED RELATIVE POSITION AND TO ACTUATE SAID SWITCH IN THE OPPOSITE SENSE WHEN SAID DEDETENT WHEEL REACHES SAID SECOND RELATIVE POSITION AT THE END OF AN INTERVAL OF TIME BEING MEASURED; AND AN INDICATOR CONNECTED TO SAID SHAFT TO INDICATE THE TIME REMAINING BEFORE THE END OF THE INTERVAL OF TIME BEING MEASURED. 